Plasma based trace metal removal apparatus and method

Abstract

A system and method for the removal of metals such as mercury from a gas stream. The method involves contacting a gas stream containing the target metals with reactive chemical species generated in a plasma device. The metal to be removed is chemically converted into forms enabling capture in either conventional particulate removal devices or in a wet scrubber for the capture of a soluble chemical species.

1. A plasma based removal apparatus for the removal of contaminants from a gas stream comprising:
 a plurality of non-thermal plasma generation devices radially arranged in a conduit; 
 a source of electrical power supplying electrical power to said plasma devices; 
 a source of plasma gas in fluid communication with said plasma devices to create an activated species within said plasma devices and discharge the activated species into a gas stream containing at least one contaminant; whereby the activated species reacts with the at least one contaminant to form at least one reactant compound; and 
 a removal device for removing the at least one reactant compound from the gas stream. 
 
     
     
       2. The removal apparatus according to  claim 1 , wherein the at least one contaminant includes at least one of a volatile metal and a semi-volatile metal. 
     
     
       3. The removal apparatus according to  claim 1 , wherein the at least one contaminant comprises mercury. 
     
     
       4. The removal apparatus according to  claim 1 , wherein said removal device is a particulate species type. 
     
     
       5. The removal apparatus according to  claim 1 , wherein said removal device is a soluble species type. 
     
     
       6. The removal apparatus according to  claim 1 , wherein said removal device is an electrostatic precipitator. 
     
     
       7. The removal apparatus according to  claim 1 , wherein said removal device is a wet scrubber. 
     
     
       8. The removal apparatus according to  claim 1 , wherein the at least one reactant compound includes at least one of a metal chloride and an oxy-chloride.